A comparison of patients with adolescent idiopathic scoliosis and Lenke C-type lumbar curves treated with selective thoracic fusion vs non-selective fusion: a 10-year follow-up study

Introduction: Selective thoracic fusion (STF) of scoliosis due to adolescent idiopathic scoliosis in patients with flexible lumbar curves is a desirable option to preserve lumbar motion segments. No prior studies have evaluated clinical, radiographic and patient-reported outcomes of this technique at 10-year follow-up. Methods: A review of a prospectively collected multicenter database was performed for patients with Lenke 1C, 2C, 3C or 4C-type scoliosis curves treated with either STF (L1 LIV and proximal) vs non-selective fusion of both curves (NSF) (L2 LIV and distal) who had a minimum of 10-year follow-up. Baseline demographics, spinal deformity characteristics, complications, lumbar motion (forward flexion and lateral bending), and SRS-22 patient reported outcomes scores were compared at first post operative, 2-year, and 10-year follow-up. Results: 52 NSF and 45 STF (97 total) patients were followed for 10 years after surgery. Preoperative main thoracic (MT, 62 ± 11° NSF vs 56 ± 10° STF, p = 0.02) and thoracolumbar (TL, 52 ± 11° NSF vs 44 ± 17° STF, p < 0.001) curves were larger in the NSF group. At 10-year follow-up, patients with NSF had smaller residual lumbar curves (17° vs 23°, p < 0.001), and no difference in forward flexion or SRS-22 scores. Lateral flexion was decreased in NSF patients (p < 0.05). More NSF patients reached clinically meaningful improvement in self-image (83% vs 60%, p = 0.02); however, there were no differences in any other subdomains of the SRS-22. There was no difference in complications or reoperations between groups. Conclusions: STF was associated with a larger residual lumbar curve at 10-year follow-up. NSF patients less lateral spinal motion but were more likely to report better self-image after surgery. Significance: Ten-year follow-up data on patients treated with two different techniques for Lenke C AIS demonstrates meaningful differences for patient decision making. STF results in better motion with slightly larger residual lumbar curves and marginally lower self-image scores, while NSF results in better self-image and lumbar curvature correction and similar complication profiles.