Clinical results and functional outcomes after three-column osteotomy at L5 or the sacrum in adult spinal deformity

Purpose: Three-column osteotomies at L5 or the sacrum (LS3COs) are technically challenging, yet they may be needed to treat lumbosacral kyphotic deformities. We investigated radiographic and clinical outcomes after LS3CO. Methods: We analyzed 25 consecutive patients (mean age 56 years) who underwent LS3CO with minimum 2-year follow-up. Standing radiographs and health-related quality-of-life scores were evaluated. A new radiographic parameter [“lumbosacral angle” (LSA)] was introduced to evaluate sagittal alignment distal to the S1 segment. Results: From preoperatively to the final follow-up, significant improvements occurred in lumbar lordosis (from − 34° to − 49°), LSA (from 0.5° to 22°), and sagittal vertical axis (SVA) (from 18 to 7.3 cm) (all, p <.01). Mean Scoliosis Research Society (SRS)-22r scores in activity, pain, self-image, and satisfaction (p <.05), and Oswestry Disability Index scores (p <.01) also improved significantly. Patients with SVA ≥ 5 cm at the final follow-up experienced less improvement in SRS-22r satisfaction scores than those with SVA < 5 cm. Patients with LSA < 20° at the final follow-up had significantly lower SRS-22r activity scores than those with LSA ≥ 20° (p =.014). Two patients had transient neurologic deficits, and 11 patients underwent revision for proximal junctional kyphosis (5), pseudarthrosis (3), junctional stenosis (2), or neurologic deficit (1). Conclusions: LS3CO produced radiographic and clinical improvements. However, patients who remained sagittally imbalanced had less improvement in SRS-22r satisfaction score than those whose sagittal imbalance was corrected, and patients who maintained kyphotic deformity in the lumbosacral spine had lower SRS-22r activity scores than those whose lumbosacral kyphosis was corrected. Graphic abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.].