Dynamic motion study of the whole lumbar spine by videofluoroscopy.

STUDY DESIGN

Dynamic lumbar flexion-extension motion was assessed by videofluoroscopy.

OBJECTIVES

To identify the motion patterns of the whole lumbar spine in normal subjects and in patients with low back pain or spondylolisthesis during actual movement.

SUMMARY OF BACKGROUND DATA

Assessment of lumbar instability on terminal radiographs is controversial. Information regarding spinal kinematics during actual movement in vivo is scarce.

METHODS

Fluoroscopic lumbar sagittal motion videos were recorded in volunteers (n = 13; mean age, 22.3) and in patients with chronic low back pain (n = 8; mean age, 43.5) and degenerative spondylolisthesis (n = 8; mean age, 63.1) while the subjects bent forward from a standing neutral position (eccentric motion) and then returned to the original position (concentric motion). The videos recorded approximately 8 seconds of motion and were converted to still images at 5 frames per second. Disc angles from the horizontal line were measured to estimate sagittal rotation of each segment. Disc degeneration was evaluated on T2-weighted midsagittal magnetic resonance image.

RESULTS

In the volunteer group, six exhibited sequentially spreading motion, four exhibited simultaneous motion, and three showed an altered motion-spreading pattern in the eccentric phase. The first two patterns were considered normal. Six (67%) of the patients with chronic low back pain also showed normal patterns, but seven (88%) of the patients with degenerative spondylolisthesis showed disordered patterns. The order of motion in the concentric phase was also different among the three groups. Prolonged deflection of the slipped segment was observed more frequently in the patients with degenerative spondylolisthesis. Disc degeneration was not always associated with motion-spreading order and the motion patterns.

CONCLUSION

Segmental instability influences the whole lumbar motion in patients with degenerative spondylolisthesis. The patients with chronic low back pain did not show a significant difference when compared with the volunteers.