ABILITY OF COTREL-DUBOUSSET INSTRUMENTATION TO PRESERVE DISTAL LUMBARMOTION SEGMENTS IN ADOLESCENT IDIOPATHIC SCOLIOSIS

Between 1985 and 1990,44 patients with adolescent idiopathic scoliosis were treated with Cotrel-Dubousset instrumentation when Harrington in strumentation would have extended into the distal lumbar spine (L3, L4 , or L5) for these curve patterns. Twenty-four of these 44 (group 1) p atients had one distal fusion level preserved using Cotrel-Dubousset i nstrumentation, whereas the other 20 patients (group II) were instrume nted/fused with Cotrel-Dubousset instrumentation to the expected Harri ngton instrumentation level in the lower lumbar spine. All patients ha ve a minimum 2-year follow-up, and the average follow-up is 39 months (range 24-74). The characteristics of the group I curves that allowed us to stop the instrumentation a level short included minimal rotation and tilt of the anticipated lowest instrumented vertebra, overall cor onal curve flexibility, and nonstructural components to the lumbosacra l region of the spine. There were no major differences between these t wo groups when comparing postoperative coronal and sagittal balance pa rameters at the most recent follow-up. In select cases, dependent on t he preoperative criteria to be discussed, Cotrel-Dubousset instrumenta tion (vs. traditional Harrington instrumentation) does allow distal lu mbar fusion levels to be saved while maintaining acceptable coronal an d sagittal balance.