Severe (>100 Degrees) Thoracic Adolescent Idiopathic Scoliosis – A Comparison of Surgical Approaches

Abstract

Study Design Retrospective. Objective Severe curves >100° in adolescent idiopathic scoliosis (AIS) are rare and require careful operative planning. The aim of this study was to assess baseline, perioperative, and 2-year differences between anterior release with posterior instrumentation (AP), posterior instrumentation with posterior column osteotomies (P), and posterior instrumentation with 3-column vertebral osteotomies (VCR). Methods Two scoliosis datasets were queried for primary cases of severe thoracic AIS (≥100°) with 2-year follow-up. Pre- and 2-year postoperative radiographic measures (2D and estimated 3D kyphosis), clinical measurements, and SRS-22 outcomes were compared between three approaches. Results Sixty-one patients were included: 16 AP (26%), 38 P (62%), 7 VCR (11%). Average age was 14.4 ± 2.0 years; 75.4% were female. Preoperative thoracic curve magnitude (AP: 112°, P: 115°, VCR: 126°, P = 0.09) and T5-T12 kyphosis (AP: 38°, P: 59°, VCR: 70°, P = 0.057) were similar between groups. Estimated 3D kyphosis was less in AP vs P (−12° vs 4°, P = 0.016). Main thoracic curves corrected to 36° in AP vs 49° and 48° for P and VCR, respectively ( P = 0.02). Change in estimated 3D kyphosis was greater in AP vs P and VCR (34° vs 13°, P = 0.009; 34° vs 7°, P = 0.046). One incomplete spinal cord injury had residual deficits (P; 1/61, 1.6%). All SRS-22 domains improved postoperatively. Conclusion All approaches obtained satisfactory coronal and sagittal correction, but AP had smaller residual coronal deformity and greater kyphosis restoration than the other approaches. This information may help inform the decision of whether to include an anterior release for large thoracic AIS curves.