Results with Zielke instrumentation for idiopathic thoracolumbar and lumbar scoliosis.

Thirty-one patients (23 adolescent, eight adult) underwent spinal fusions with Zielke instrumentation for idiopathic thoracolumbar and lumbar scoliosis. Their curves averaged 55.2 degrees. In most patients the length of fusion did not extend beyond the major curve. Correction of scoliosis was 82% in adolescents and 59% in the adults. The kyphotic component of the curves was corrected from an average of 21 degrees to 8 degrees. Correction of the spinal vertebra rotation was 46% in the adolescent patients. The tilt angle of the vertebra at the lower end of the curve was reduced significantly. The fusion rate was 93.5%. Two of the adult patients developed pseudarthrosis. Major complications were not encountered. The Zielke instrumentation system in the management of idiopathic thoracolumbar and lumbar scoliosis offers the advantages of a relatively good correction and minimal segment fusion.