Anterior spinal fusion versus posterior spinal fusion for moderate lumbar/thoracolumbar adolescent idiopathic scoliosis: a prospective study.

STUDY DESIGN: A prospective study.

OBJECTIVE: Comparison study of radiologic and clinical outcomes, efficiency, and cost between anterior spinal fusion (ASF) and posterior spine fusion (PSF) in surgical treatment of moderate lumbar/thoracolumbar adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA: ASF and PSF indicated for lumbar and thoracolumbar adolescent idiopathic scoliosis surgical treatment have respective advantages and disadvantages. However, up until today, a related prospective AIS comparative study has rarely been reported.

METHODS: Thirty-two cases in this prospective study with patients enrolled in either method A or B alternately in a sequence were divided into 2 groups. Group A underwent ASF with single solid rod and single screw constructs, and group B underwent PSF with segmental total pedicle screw system. Inclusion criteria were: (1) AIS diagnosis; (2) diagnosis classification as Lenke5CN type; (3) Cobb angles 35 degrees-60 degrees on anteroposterior view radiographs. Exclusion criteria were: (1) a history of spinal surgery; (2) age younger than 10 years; (3) Risser sign 0 degree; (4) lumbar/thoracolumbar kyphosis. All patients were observed with 2-year minimum follow-up (24-46 months). Clinical and radiologic outcomes of both groups A and B were analyzed.

RESULTS: Statistical t test or Mann-Whitney U test demonstrated no significant difference in preoperative age (P = 0.380), Risser sign (P = 0.733), magnitude (P = 0.936), flexibility (P = 0.815), apical vertebra rotation (AVR, P = 0.756), and apical vertebra translation (AVT, P = 0.355) of the lumbar/thoracolumbar curves, trunk shift (TS, P = 0.448), sagittal kyphosis from T5-T12 (P = 0.792) and sagittal lordosis from L1-L5 (P = 0.299). Average coronal correction of thoracolumbar/lumbar curves was 83% after surgery and 77% at follow-up in group A and 87% after surgery and 82% at follow-up in group B (P = 0.236 and P = 0.138). No significant differences were observed regarding correction of sagittal alignment, TS, AVT, AVR and hospitalization days on last follow-up between both groups (P > 0.05). No pseudarthrosis, reoperation, neurologic complications, infection, and no other problems were observed. Excellent clinical fusion results were present in all patients on their last follow-up. However, significant differences were evident in group A in regards to reduced operative time (P = 0.046), reduced estimated blood loss (P = 0.003), decreased blood transfusion (P = 0.006), reduced implants cost and hospitalization expenses (P = 0.000). Additionally, group A had shorter fusion levels than group B (p50 = 4 vs. p50 = 5, P = 0.003).

CONCLUSION: ASF versus PSF comparison in treating moderate lumbar/thoracolumbar AIS did not show significant differences in regards to safety or efficacy but demonstrated shorter fusion levels, reduced surgical trauma and costs in ASF.