Introduction and Objectives: This is a retrospective radiographic study of results of surgical correction of thoracolumbar and King I scoliosis using segmental instrumentation.

Materials and Methods: This study includes 44 patients (41 female, 3 male) with an average age of 16.8 years (12-40) and 5.9 years average progression. The number of instrumented levels was 5.1 (4–7). Curve magnitude, T1–S1 imbalance, and the angles of the instrumented zone were measured using teleradiographic studies with an anteroposterior view. Thoracic kyphosis and lumbar lordosis were measured in the sagittal plane, and the thoracic and lumbar regions were measured in the instrumented area.

Results: On the anteroposterior view, average magnitude of principal preoperative curve, postoperative curve, and final result was 48°, 11.9°, and 14.7°, respectively. A final correction of 69.3% was obtained. T1–S1 imbalance improved from an initial 2.1cm to 1.9cm postoperatively and a final result of 0.5cm. On the lateral view, preoperative, postoperative, and final thoracic kyphosis were 29.5°, 27.8°, and 30.4°, respectively. Average figures for lumbar lordosis were 59.2°, 55.6°, and 61.1°. The instrumented thoracic zone went from 0.8° kyphosis preoperatively to 4.7° final kyphosis, and the lumbar area of instrumentation went from 9.7° preoperative lordosis to a final angle of 10.4°.

Discussion and Conclusions: In our experience, correction of thoracolumbar and King I scoliosis using anterior instrumentation has given good results, obtaining an initial 75% correction of the principal curve and an average loss of only 3° on follow-up. In the sagittal plane, there is no loss of kyphosis and lordosis, both of which are within normal physiological ranges. Thoracic kyphosis was increased 3.9° in the instrumented zone, and although instrumented lordosis did not improve, a kyphotic effect was observed.