Staged lateral lumbar interbody fusion combined with mini-open posterior screw fixation with or without facetectomy for coronal and sagittal realignment in degenerative spinal deformity: A retrospective cohort study.

INTRODUCTION: Coronal imbalance in degenerative spinal deformity is difficult to correct, particularly when the fractional curve is rigid and the lumbosacral foundation is oblique. RESEARCH QUESTION: Is staged lateral lumbar interbody fusion with targeted mini-open posterior correction associated with stepwise coronal and sagittal realignment and maintenance of coronal alignment at follow-up? MATERIAL AND METHODS: We retrospectively reviewed 51 consecutive patients treated with multi-level lateral lumbar interbody fusion followed by posterior percutaneous fixation with or without targeted mini-open osteotomy. Standing full-length radiographs were assessed preoperatively, after stage I, after stage II, and at latest follow-up. Coronal endpoints were coronal Cobb angle, coronal vertical axis, and fractional-curve take-off angle. Sagittal endpoints included lumbar lordosis, pelvic incidence minus lumbar lordosis mismatch, T1 pelvic angle, and sagittal vertical axis. Clinical outcomes were assessed preoperatively and at follow-up. RESULTS: Coronal Cobb angle improved from 35.62° preoperatively to 21.93° after stage I, 10.20° after stage II, and 10.91° at follow-up. Coronal vertical axis improved from 28.50 mm to 14.95 mm, and fractional-curve take-off angle from 17.28° to 5.88°. Lumbar lordosis increased from 22.40° to 35.66°, while pelvic incidence minus lumbar lordosis mismatch, T1 pelvic angle, and sagittal vertical axis also improved. Back-pain visual analog scale and Oswestry Disability Index improved significantly at follow-up. DISCUSSION AND CONCLUSION: Staged lateral lumbar interbody fusion with targeted mini-open posterior correction was associated with stepwise coronal and sagittal realignment, and the improvement in mean coronal alignment was maintained at follow-up.