spinal fusion. A cohort study of complications. reoperations. and resource use in the Medicare population. Spine 18.1463-1470 (1993). 8. Singh. K. et al. Congenital lumbar spinal stenosis: a prospective. control-matched. cohort radiographic analysis. Spine J. 5.615-622 (2005). 9. Tubbs. R. S. & O