Original Article: PDF OnlyAnalysis of the Primary and Compensatory Curvatures following Zielke Instrumentation for Idiopathic ScoliosisPUNO, ROLANDO M., MD; JOHNSON, JOHN R., MD; OSTERMANN, PETER A W., MD; HOLT, RICHARD T., MDAuthor Information From the Department of Orthopaedic Surgery, University of Louisville, and The Kenton D. Leatherman Spine Center, Louisville, Kentucky Spine: July 1989 - Volume 14 - Issue 7 - p 738-743 Buy Abstract The behavior of the primary and compensatory curvatures of 34 patients (follow-up, 24–48 months) with solid fusions following Zielke instrumentation were evaluated. All patients showed correction of their primary curvatures (range, 40–112%; average, 70%) postoperatively. Thirty-one showed loss of correction (range, 2.8–78.5%; mean, 25%). There was a higher tendency to lose correction if the curve was fused short of the Cobb measurement (35% vs. 17%). The majority of both the thoracic and the lumbosacral compensatory curves improved postoperatively (average of 38.6 and 66%, respectively). However, when the instrumentation was carried cephalad to the primary curve, there was a high probability that the upper compensatory curve would be worse after the surgery. Trunk list tended to improve during the course of follow-up. © Lippincott-Raven Publishers.