139. Segmental lordosis restoration using ALIF vs TLIF in adults with flatback deformity

BACKGROUND CONTEXT Few studies investigate segmental lordosis restoration after long fusion with anterior (ALIF) vs transforaminal lumbar interbody fusion (TLIF) for adults with flatback deformity. PURPOSE Our objective was to compare segmental lordosis restoration, health-related quality-of-life (HRQL), and complications associated with L4-S1 ALIF vs TLIF in operative treatment of flatback deformity. STUDY DESIGN/SETTING Retrospective review of a prospectively collected multicenter consecutive case registry. PATIENT SAMPLE Database enrollment required age ≥18 years, scoliosis ≥20°, sagittal vertical axis (SVA) ≥5cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°. OUTCOME MEASURES Radiographic correction (including L4-S1 segmental lordosis), HRQL (Oswestry Disability Index [ODI], Short Form-36 [SF-36] scores, Scoliosis Research Society-22 [SRS-22r] scores), and complications. Methods Prospective multicenter data were reviewed. Study inclusion required pelvic incidence to lumbar lordosis mismatch ≥10° (flatback), index ALIF vs TLIF at L4-L5 and/or L5-S1, and minimum 2-year follow-up. Cage details (height and lordosis) were also assessed. Results Of 222 consecutive patients, 157 (71%) achieved 2-year follow-up (age=63±10years, women=82%, ALIF=43%, TLIF=57%). Index operations had 12±3 posterior levels, iliac fixation=93%, and ALIF/TLIF at L4-L5 (66%) and L5-S1 (85%). ALIF vs TLIF cages were similar in height, but cage lordosis was greater for ALIF: L4-L5 (9°±5° vs 7°±2°, p=0.025) and L5-S1 (14°±9° vs 7°±3°, p Conclusions Although it appears that most LL correction occurred between T12-L4, use of ALIF did provide superior segmental lordosis restoration at L4-S1 (compared to TLIF). Despite more rod fractures in TLIF patients, HRQL was similar for ALIF vs TLIF in this study. Further work is warranted to clarify when it is optimal to perform ALIF vs TLIF in this population. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.