Study design: A retrospective study was conducted of patients with untreated adult-type idiopathic lumbar scoliosis.
Objectives: To construct a mathematical formula that provides accurate progression of an idiopathic adult lumbar scoliosis using initial roentgenographic parameters.
Summary of background data: Osteoporosis, lateral spondylolisthesis of L2-L4, and degeneration of disc and joint may contribute to a poor prognosis for lumbar adult-type scoliosis.
Methods: Seven roentgenographic parameters taken from the standing roentgenograms of 91 patients with a scoliosis of more than 10 degrees Cobb angle and who were included in a follow-up for more than 2 years, were put into a multiple regression analysis to observe the relative weight of each in the progression of the scoliosis.
Results and conclusions: Only lateral spondylolisthesis of the apical vertebra, Harrington factor, and disc index were related to progression of the scoliosis. Using the mathematical formula, the real progression of lumbar scoliosis can be predicted within an average of 0.85 degrees +/- 3.76 degrees.