Anterior spinal fusion with Zielke instrumentation for idiopathic scoliosis. A frontal and sagittal curve analysis in 36 patients.

The authors have reviewed the records of 36 patients with idiopathic scoliosis who underwent a single-stage anterior spinal fusion with Zielke instrumentation to determine if any adverse frontal or secondary sagittal deformities or changes in balance resulted from the surgery. Spontaneous correction of uninstrumented thoracic curves was noted in five patients with double-major curves, and frontal balance was maintained or improved after operation in all but four patients. Kyphosis was increased in the instrumented segments in all patients. In the uninstrumented segments, however, thoracic kyphosis and lumbar lordosis were decreased in all but five patients after operation, whereas overall sagittal balance was not adversely affected by the surgery in any patient.