Radiologic diagnosis of degenerative lumbar spinal instability. x

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Dupuis PR. Yong-Hing K. Cassidy JD. Kirkaldy-Willis WH. x Spine. [JC:uxk] 10(3):262-76, 1985 Apr. x A lumbar motion segment is considered to be unstable when it exhibits x abnormal movement. This movement can be abnormal in quality (abnormal x coupling patterns) or in quantity (abnormal increased motion). This x instability can be symptomatic or asymptomatic, depending on the demands x made on the motion segment. Pain is a signal of impending or actual tissue x damage, and when present it indicates that a certain mechanical threshold x has been reached or transgressed. Repeated transgressions will damage the x stabilizing structures beyond physiologic repair, thus putting abnormal x demands on secondary restraints. Radiographic study with dynamic views x obtained in the frontal and lateral planes identify unstable states in the x clinical environment. x