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 w hole lumbar spine in normal subjects and in patients with low back pai n or spondylolisthesis during actual movement. Summary of Background D ata. Assessment of lumbar instability on terminal radiographs is contr oversial. Information regarding spinal kinematics during actual moveme nt In vivo Is scarce. Methods. Fluoroscopic lumbar sagittal motion vid eos were recorded in volunteers (n = 13; mean age, 22.3) and in patien ts with chronic low hack pain (n = 8; mean age, 43.5) and degenerative spondylolisthesis (n = 8; mean age, 63.1) while the subjects bent for ward from a standing neutral position (eccentric motion) and then retu rned 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 meas ured to estimate sagittal rotation of each segment, Disc degeneration was evaluated on T2-weighted mid-sagittal magnetic resonance image. Re sults. In the volunteer group, six exhibited sequentially spreading mo tion, four exhibited simultaneous motion, and three showed an altered motion-spreading pattern in the eccentric phase. The first two pattern s were considered normal. Six (67%) of the patients with chronic low b ack pain also showed normal patterns; but seven (88%) of the patients with degenerative spondylolisthesis showed disordered patterns. The or der of motion in the concentric phase was also different among the thr ee groups. Prolonged deflection of the slipped segment was observed mo re frequently in the patients with degenerative spondylolisthesis, Dis c degeneration was not always associated with motion-spreading order a nd the motion patterns. Conclusion. Segmental instability influences t he whole lumbar motion in patients with degenerative spondylolisthesis . The patients with chronic low back pain did not show a significant d ifference when compared with the volunteers.