Hybrid Thoracic Posterior Spinal Fusion Combined with Posterior Lumbar Vertebral Body Tethering in Adolescent Idiopathic Scoliosis: A Motion- Preserving Strategy

Abstract

Purpose:

Posterior spinal fusion (PSF) provides reliable correction in adolescent idiopathic scoliosis (AIS) but sacrifices lumbar motion when extended distally. Vertebral body tethering (VBT) preserves motion but carries significant mechanical complication rates in thoracic spine. We evaluated a hybrid strategy combining thoracic PSF with posterior lumbar vertebral body tethering (PLVBT) to preserve distal lumbar mobility while maintaining deformity correction.

Methods:

Seventeen consecutive Lenke 1C, 3C or 6C AIS patients underwent thoracic PSF combined with PLVBT. Primary outcome was lumbar Cobb angle change at 2 years. Secondary outcomes included thoracic Cobb angle, sagittal parameters, perioperative data, and complications. Paired t-tests and Cohen's d effect sizes were calculated.

Results:

Lumbar Cobb angle improved from 51° (± 7°) to 19° ( ± 8°) at 2 years (p < 0.0001, d = 4.21). Thoracic Cobb angle improved from (59° ± 12°) to (34° ± 8°) (p < 0.0001, d = 2.85). Thoracic kyphosis significantly increased from 14° (± 9°) to 24° (± 9)° (p = 0.01, d = 1.11). Lumbar lordosis didn’t change. No tether rupture occurred. Complication rate was 17.6%.

Conclusion:

Hybrid thoracic PSF combined with PLVBT achieved large, durable correction while theoricaly preserving lumbar mobility. This approach may represent a rational alternative to extended lumbar fusion in selected AIS patients.