Idiopathic scoliosis instrumentation using the Lea Plaza sublaminar frame. A preliminary report

We reviewed 28 patients with idiopathic scoliosis operated on using the segmental sublaminar instrumentation devised by Lea Plaza. The results at 2 years show that the spine is rebalanced and normal alignment in the sagittal plane is obtained. The biplanar correction of double curves averaged 64% with a loss of 10% at 2 years. The upper and lower limits of the fusion area must be determined accurately in relation to the pattern of the curve. Combined anterior and posterior arthrodesis is advised in flexible or rigid curves of more than 60 degrees in skeletally immature or mature patients respectively. In double curves over-correction of the primary curve behind its flexibility index, and inclusion of the mobile transitional segments in the fusion area produce decompensation in the frontal plane. One case of total loosening of the frame occurred, but there was no protrusion of the frame, no fractures of the laminae, no sepsis, no pseudarthrosis and no permanent neural damage.