Selective Thoracic Fusion In Lenke Type 1 Or 2 Adolescent Idiopathic Scoliosis With Posterior Simultaneous Correction By Bilateral Corrective Rod

Objective To evaluate the outcomes of the strategy of selective thoracic fusion in Lenke type 1 or 2 adolescent idiopathic scoliosis(AIS) with posterior simultaneous correction by bilateral corrective rod.Method 41 AIS patients(15 males, 26 females, aged avergely 14.7 years) with 32 Lenke type l(lumbar modifier A=20,B=9,C=3)and 9 Lenke type 2(lumbar modifier A=5,B=3,C=1) underwent selective thoracic fusion with posterior simultaneous correction by bilateral corrective rod by the same surgeon. The mean follow-up was 28.2 months(ranged from 24 to 41 months). Radiographs were measured and analyzed before surgery,immediately after surgery,and at most recent follow-up.Result The mean preoperative thoracic curve was 45.064°±11.615°and had corrected to 8.664°±4.474° postoperatively for a(81.092±6.506) % instrumented correction and to 9.541°±4.373° at the final follow-up with the correction loss of 0.878°±2.811°. The lumbar curve improved from 27.605°±8.403° preoperatively to 7.135°±4.691° postoperatively with a spontaneous correction of(74.215±12.204)%and to 5.640°±6.987° at the final follow-up. Kyphosis of T5-T12 increased from 13.497°±12.765° preoperatively to 19.732°±4.514° postoperatively which was 20.887°±4.721° at the most recent follow-up. Lower instrumented vertebra disc angle decreased from 4.779°±3.485° preoperatively to 1.435°±2.283° postoperatively, which improved to-0.484°±4.213° at the final follow-up. Proximal Thoracic Curve(PTC)?radiographic shoulder height(RSH)?clavicle angle(CA)?lower instrumented vertebra tilting(LIVT) and sagittal vertical axis(SVA) improved after surgery and did not change significantly during the follow-up. 2 patients were found with obviously spine decompensation, one of which was Adding-on phenomenon,and the other was sagittal discompensation who was serve unbalanced. As they did not deteriorate,they remained to be observed. There were no neurological complications, implant-related complications and wound infection.Conclusion Selective thoracic fusion by posterior bilateral rod simultaneous correction was a safe and effective strategy to treat Lenke type 1 or 2 AIS with the advantages of not only attaining satisfactory correction of instrumented thoracic curve and spontaneous lumbar curve but also manintaining sagittal profile and decreasing potentially the risk of spinal cord and nerve injury while saving more mobile segments.