Selective Thoracic Fusion for Idiopathic Scoliosis: A Comparison of Three Surgical Techniques with Minimum 5-year Follow-up.

STUDY DESIGN Single-center retrospective review of outcomes among three surgical techniques in the treatment of thoracic idiopathic scoliosis (T-AIS) with a follow-up of at least 5 years. OBJECTIVE To investigate how outcomes compare in video-assisted anterior thoracic instrumentation (VATS), all hooks/hook-pedicle screw hybrid instrumentation (HHF), and all pedicle screw instrumentation (PSF) techniques for T-AIS. SUMMARY OF BACKGROUND DATA Studies comparing outcomes for anterior vs posterior fusion for T-AIS are few and with short follow-up. METHODS Three groups of patients with T-AIS who underwent thoracic fusion were included in this study: 98 patients with mean curve of 49.0° ± 9.5° underwent VATS (Group 1); 44 patients with mean curve of 51.1° ± 7.4° underwent HHF (Group 2); and 47 patients with mean curve of 47.6° ± 9.9° underwent PSF (Group 3). Radiological outcomes were compared at pre-operative, and up to 5 years. Surgical outcomes were noted until latest follow-up. RESULTS Group 1 had less blood loss, less fusion levels, longer surgical time, and longer hospital stay compared to the other groups (p < .01). Groups 1 and 3 were comparable in all time periods with 78.8% and 78.2% immediate curve correction, and 72.9% and 72.1% at 5 years, respectively. Group 2 had lower correction in all time periods (p < .0001). Thoracic kyphosis and lumbar lordosis decreased in Group 3, but improved in both Groups 1 and 2 (p < .0001). Group 1 had more respiratory complications. The posterior groups had more deep wound infections. Two patients in Group 1 and one patient in Group 2 required revision surgery for implant-related complications. Re-operations for deep wound infections were noted only in the posterior groups. CONCLUSION This is the first report comparing 5 year outcomes between anterior and posterior surgery for T-AIS. All three surgical methods resulted in significant and durable scoliosis correction, however curve correction using HHF was inferior to both VATS and PSF with the latter two groups achieving similar coronal correction. However, VATS involved fewer segments, kyphosis improvement, and no deep wound infection whereas PSF has less surgical time, shorter hospital stays, and no revision surgery from implant-related complications.Level of Evidence: 3.