Clinical validation of functional flexion-extension roentgenograms of the lumbar spine.

The purpose of this study was to determine the clinical validity of functional flexion-extension roentgenograms of the lumbar spine in a defined patient population. One hundred and one adults with low-back pain or functional disorders underwent passive functional flexion-extension examinations. Their roentgenograms were analyzed using a computer-assisted method to determine segmental motion parameters such as rotation and translation of the lumbar vertebrae. The patient population was broken down into five groups with similar pathologies or physical conditions, and their motion parameters compared to a normal population and to each other. It was found that all of the patient groups exhibited significantly hypomobile motion, spread equally among all levels, in comparison to the normal population, except for the group of high-performance athletes, who had significant hypermobility. The uniform spread of hypomobility limits the ability to distinguish with any confidence between the four pathologic groups by their motion. Thus, we believe that the analysis of the segmental motion of the lumbar spine using passive flexion-extension roentgenograms does not aid in differentiating the underlying pathologic condition of patients with low-back pain, and that no useful information can be derived form this procedure, especially in relation to the need for surgical intervention.