Selective Anterior Thoracolumbar Fusion in Adolescent Idiopathic Scoliosis Long-Term Results After 17-Year Follow-Up

Study Design. Prospectively updated long-term data and retrospective case series analysis. Objective. To report the long-term results of selective anterior instrumented thoracolumbar (ThL) fusion in adolescent idiopathic scoliosis (AIS). Summary of Background Data. The results of anterior selective fusion in AIS have been reported up to 2 and 5 years follow-up. However, there is a lack of evidence of long-term results of this surgical approach. Methods. Forty-two consecutive patients with main thoracolumbar/ lumbar AIS who had undergone surgery for a selective anterior ThL instrumented fusion with more than 12 years of follow-up met inclusion criteria. Preoperative, postoperative (1yr), and final updated radiographic parameters were recorded. Final ODI and SRS-22 questionnaires were evaluated. Results. Thirty-five patients were finally recruited (5 were lost and 2 refused). The mean age at surgery was 16.6 years. The mean final follow-up was 17.3 years (12-24 yr). The ThL preoperative Cobb was 49.5 degrees +/- 9, obtaining a postoperative correction of 79% +/- 13 and final correction of 72% +/- 18. The preoperative thoracic curve (31.4 degrees +/- 14.2) obtained a spontaneous postoperative correction to 18.4 degrees +/- 11.9, maintained at final follow-up (17.8 degrees +/- 10.8). Apical vertebral rotation improved from 25.8 degrees +/- 7.8 to 9.2 degrees +/- 5.5 and finally to 8 degrees +/- 5.2 (P = 0.001). Sagittal parameters (T5-T12 = 27.2 degrees and L1S1 = 56.9 degrees) did not change significantly postoperatively nor by final follow-up. Coronal balance improved from 2.4 cm to 1.6cm postoperatively and 0.8 cm at final follow-up (P = 0.006). The disc angulation below the last instrumented vertebra improved with follow-up from 7.6 degrees to 5.7 degrees (P = 0.012). There were no revision surgeries or infections. One patient showed a symptomatic lower disc degeneration requiring lumbar pain surgery. Final SRS-22 global score was 4.3/5. The final ODI scored 6/100. Conclusion. In the long term, selective anterior thoracolumbar instrumentation with a single solid rod in AIS maintained good corrections on the three planes with no major complications or infections, no revision surgeries, and with satisfactory final functional and clinical outcomes.